using System;
using System.Collections.Generic;
using System.Linq;
using System.Numerics;
using System.Reflection;
using MLEM.Data.Json;
using Newtonsoft.Json;
namespace MLEM.Data {
///
/// A dynamic enum is a class that represents enum-like single-instance value behavior with additional capabilities, including dynamic addition of new arbitrary values.
/// A dynamic enum uses as its underlying type, allowing for an arbitrary number of enum values to be created, even when a -like structure is used that would only allow for up to 64 values in a regular enum.
/// All enum operations including , , and are supported and can be implemented in derived classes using operator overloads.
/// To create a custom dynamic enum, simply create a class that extends . New values can then be added using , or .
///
///
/// To include enum-like operator overloads in a dynamic enum named MyEnum, the following code can be used:
///
/// public static implicit operator BigInteger(MyEnum value) => GetValue(value);
/// public static implicit operator MyEnum(BigInteger value) => GetEnumValue<MyEnum>(value);
/// public static MyEnum operator |(MyEnum left, MyEnum right) => Or(left, right);
/// public static MyEnum operator &(MyEnum left, MyEnum right) => And(left, right);
/// public static MyEnum operator ^(MyEnum left, MyEnum right) => Xor(left, right);
/// public static MyEnum operator ~(MyEnum value) => Neg(value);
///
///
[JsonConverter(typeof(DynamicEnumConverter))]
public abstract class DynamicEnum {
private static readonly Dictionary> Values = new Dictionary>();
private static readonly Dictionary> FlagCache = new Dictionary>();
private static readonly Dictionary> ParseCache = new Dictionary>();
private readonly BigInteger value;
private Dictionary allFlagsCache;
private Dictionary anyFlagsCache;
private string name;
///
/// Creates a new dynamic enum instance.
/// This constructor is protected as it is only invoked via reflection.
///
/// The name of the enum value
/// The value
protected DynamicEnum(string name, BigInteger value) {
this.value = value;
this.name = name;
}
///
/// Returns true if this enum value has ALL of the given flags on it.
/// This operation is equivalent to .
///
///
/// The flags to query
/// True if all of the flags are present, false otherwise
public bool HasFlag(DynamicEnum flags) {
if (this.allFlagsCache == null)
this.allFlagsCache = new Dictionary();
if (!this.allFlagsCache.TryGetValue(flags, out var ret)) {
// & is very memory-intensive, so we cache the return value
ret = (GetValue(this) & GetValue(flags)) == GetValue(flags);
this.allFlagsCache.Add(flags, ret);
}
return ret;
}
///
/// Returns true if this enum value has ANY of the given flags on it
///
///
/// The flags to query
/// True if one of the flags is present, false otherwise
public bool HasAnyFlag(DynamicEnum flags) {
if (this.anyFlagsCache == null)
this.anyFlagsCache = new Dictionary();
if (!this.anyFlagsCache.TryGetValue(flags, out var ret)) {
// & is very memory-intensive, so we cache the return value
ret = (GetValue(this) & GetValue(flags)) != 0;
this.anyFlagsCache.Add(flags, ret);
}
return ret;
}
///
public override string ToString() {
if (this.name == null) {
var included = new List();
if (GetValue(this) != 0) {
foreach (var v in GetValues(this.GetType())) {
if (this.HasFlag(v) && GetValue(v) != 0)
included.Add(v);
}
}
this.name = included.Count > 0 ? string.Join(" | ", included) : GetValue(this).ToString();
}
return this.name;
}
///
/// Adds a new enum value to the given enum type
///
/// The name of the enum value to add
/// The value to add
/// The type to add this value to
/// The newly created enum value
/// Thrown if the name or value passed are already present
public static T Add(string name, BigInteger value) where T : DynamicEnum {
if (!Values.TryGetValue(typeof(T), out var dict)) {
dict = new Dictionary();
Values.Add(typeof(T), dict);
}
// cached parsed values and names might be incomplete with new values
FlagCache.Remove(typeof(T));
ParseCache.Remove(typeof(T));
if (dict.ContainsKey(value))
throw new ArgumentException($"Duplicate value {value}", nameof(value));
if (dict.Values.Any(v => v.name == name))
throw new ArgumentException($"Duplicate name {name}", nameof(name));
var ret = Construct(typeof(T), name, value);
dict.Add(value, ret);
return (T) ret;
}
///
/// Adds a new enum value to the given enum type .
/// This method differs from in that it automatically determines a value.
/// The value determined will be the next free number in a sequence, which represents the default behavior in an enum if enum values are not explicitly numbered.
///
/// The name of the enum value to add
/// The type to add this value to
/// The newly created enum value
public static T AddValue(string name) where T : DynamicEnum {
BigInteger value = 0;
if (Values.TryGetValue(typeof(T), out var defined)) {
while (defined.ContainsKey(value))
value++;
}
return Add(name, value);
}
///
/// Adds a new flag enum value to the given enum type .
/// This method differs from in that it automatically determines a value.
/// The value determined will be the next free power of two, allowing enum values to be combined using bitwise operations to create -like behavior.
///
/// The name of the enum value to add
/// The type to add this value to
/// The newly created enum value
public static T AddFlag(string name) where T : DynamicEnum {
BigInteger value = 0;
if (Values.TryGetValue(typeof(T), out var defined)) {
while (defined.ContainsKey(value))
value <<= 1;
}
return Add(name, value);
}
///
/// Returns a collection of all of the enum values that are explicitly defined for the given dynamic enum type .
/// A value counts as explicitly defined if it has been added using , or .
///
/// The type whose values to get
/// The defined values for the given type
public static IEnumerable GetValues() where T : DynamicEnum {
return GetValues(typeof(T)).Cast();
}
///
/// Returns a collection of all of the enum values that are explicitly defined for the given dynamic enum type .
/// A value counts as explicitly defined if it has been added using , or .
///
/// The type whose values to get
/// The defined values for the given type
public static IEnumerable GetValues(Type type) {
return Values.TryGetValue(type, out var ret) ? ret.Values : Enumerable.Empty();
}
///
/// Returns the bitwise OR (|) combination of the two dynamic enum values
///
/// The left value
/// The right value
/// The type of the values
/// The bitwise OR (|) combination
public static T Or(T left, T right) where T : DynamicEnum {
return GetEnumValue(GetValue(left) | GetValue(right));
}
///
/// Returns the bitwise AND (&) combination of the two dynamic enum values
///
/// The left value
/// The right value
/// The type of the values
/// The bitwise AND (&) combination
public static T And(T left, T right) where T : DynamicEnum {
return GetEnumValue(GetValue(left) & GetValue(right));
}
///
/// Returns the bitwise XOR (^) combination of the two dynamic enum values
///
/// The left value
/// The right value
/// The type of the values
/// The bitwise XOR (^) combination
public static T Xor(T left, T right) where T : DynamicEnum {
return GetEnumValue(GetValue(left) ^ GetValue(right));
}
///
/// Returns the bitwise NEG (~) combination of the dynamic enum value
///
/// The value
/// The type of the values
/// The bitwise NEG (~) value
public static T Neg(T value) where T : DynamicEnum {
return GetEnumValue(~GetValue(value));
}
///
/// Returns the representation of the given dynamic enum value
///
/// The value whose number representation to get
/// The value's number representation
public static BigInteger GetValue(DynamicEnum value) {
return value?.value ?? 0;
}
///
/// Returns the defined or combined dynamic enum value for the given representation
///
/// The value whose dynamic enum value to get
/// The type that the returned dynamic enum should have
/// The defined or combined dynamic enum value
public static T GetEnumValue(BigInteger value) where T : DynamicEnum {
return (T) GetEnumValue(typeof(T), value);
}
///
/// Returns the defined or combined dynamic enum value for the given representation
///
/// The type that the returned dynamic enum should have
/// The value whose dynamic enum value to get
/// The defined or combined dynamic enum value
public static DynamicEnum GetEnumValue(Type type, BigInteger value) {
// get the defined value if it exists
if (Values.TryGetValue(type, out var values) && values.TryGetValue(value, out var defined))
return defined;
// otherwise, cache the combined value
if (!FlagCache.TryGetValue(type, out var cache)) {
cache = new Dictionary();
FlagCache.Add(type, cache);
}
if (!cache.TryGetValue(value, out var combined)) {
combined = Construct(type, null, value);
cache.Add(value, combined);
}
return combined;
}
///
/// Parses the given into a dynamic enum value and returns the result.
/// This method supports defined enum values as well as values combined using the pipe (|) character and any number of spaces.
/// If no enum value can be parsed, null is returned.
///
/// The string to parse into a dynamic enum value
/// The type of the dynamic enum value to parse
/// The parsed enum value, or null if parsing fails
public static T Parse(string strg) where T : DynamicEnum {
return (T) Parse(typeof(T), strg);
}
///
/// Parses the given into a dynamic enum value and returns the result.
/// This method supports defined enum values as well as values combined using the pipe (|) character and any number of spaces.
/// If no enum value can be parsed, null is returned. ///
/// The type of the dynamic enum value to parse
/// The string to parse into a dynamic enum value
/// The parsed enum value, or null if parsing fails
public static DynamicEnum Parse(Type type, string strg) {
if (!ParseCache.TryGetValue(type, out var cache)) {
cache = new Dictionary();
ParseCache.Add(type, cache);
}
if (!cache.TryGetValue(strg, out var cached)) {
BigInteger? accum = null;
foreach (var val in strg.Split('|')) {
foreach (var defined in GetValues(type)) {
if (defined.name == val.Trim()) {
accum = (accum ?? 0) | GetValue(defined);
break;
}
}
}
if (accum != null)
cached = GetEnumValue(type, accum.Value);
cache.Add(strg, cached);
}
return cached;
}
private static DynamicEnum Construct(Type type, string name, BigInteger value) {
var constructor = type.GetConstructor(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, null, new[] {typeof(string), typeof(BigInteger)}, null);
return (DynamicEnum) constructor.Invoke(new object[] {name, value});
}
}
}